1. Field of the Invention
The present invention relates to a crystalline vitamin D derivative useful for treating or preventing a disease due to abnormality in calcium absorption, transportation or metabolism, tumor or psoriasis, a method for preparing the derivative and a medical use thereof. Further, the present invention relates to a stable pharmaceutical composition containing the vitamin D derivative.
2. Description of the Related Art
As one of vitamin D derivatives, (5Z,7E,23S)-26,26,26,27,27,27-hexafluoro-9,10-secocholesta-5,7,10(19)-trie n-1.alpha.,3.beta.,23,25-tetraol of formula (2): ##STR1## is known to be useful as a medicine for treating or preventing various bone diseases due to abnormality in calcium absorption, transportation or metabolism (for example, rickets, osteomalacia and osteoporosis), tumor or psoriasis (Japanese Patent KOKAI (Laid Open) No. 63-45249 and U.S. Pat. No. 5,030,626).
Neither Japanese Patent KOKAI (Laid-Open) No. 63-45249 nor U.S. Pat. No. 5,030,626 specifically disclose a vitamin D derivative hydrate, although they specifically disclose the vitamin D derivative in the form of non-crystal which is amorphous or non-crystalline powder.
In the meantime, it is known that an activated vitamin D is topically administered in the form of an external formulation to treat intractable skin diseases including psoriasis (EP 129003, EP 177920, WO 86/02527 and Japanese Patent KOKAI (Laid-Open) No. 63-183534).
The vitamin D derivative of formula (2) has such problems as poor preservation stability and difficult handling in preparation of a pharmaceutical formulation.
In general, an activated vitamin D is chemically unstable, particularly under the exposure of light. Thus, when administered in the form of an external formulation, the activated vitamin D is particularly unstable in the therapeutical use.
Accordingly, it is important to provide a pharmaceutical composition containing an activated vitamin D wherein the vitamin D is stable even under the exposure of light after externally administered.